1. Field of the Invention
The present invention relates generally to valve stems and valve stem assemblies for vehicle tires and, in particular, to a valve stem adaptor for use in connection with a valve stem assembly for a tire.
2. Description of Related Art
In order to inflate and deflate tires on vehicles, a valve stem assembly is required, which allows the passage of pressurized air through the assembly into the tire or tube. Commercial and consumer vehicles, such as cars, trucks, buses, etc., require such a valve stem assembly for tire maintenance. While both consumer and commercial vehicles require such assemblies, increased maintenance is required on a commercial valve stem assembly, since commercial vehicles are used much more frequently.
A typical problem on a commercial vehicle is the leakage of air at the base of the valve stem assembly. This problem is amplified when dealing with tubeless heavy truck tire rims. In order to avoid or minimize such leakage, prior art methods have utilized a rubber grommet near the base of the valve stem assembly to assist in forming a seal between the valve stem assembly and the inner wall of the tire rim. However, these grommets and other parts that are manufactured from rubber are particularly subject to wear-and-tear and degradation. When the rubber grommet begins to degrade or otherwise fail, the seal between the valve stem assembly and the inner wall of the tire rim is compromised, which results in air leakage.
When an air leak is detected, the only method of stopping such leakage is by removal of the rim from the truck and the re-tightening of the valve stem assembly and, in particular, further pressing the rubber grommet against the rim to reestablish the seal. If the rubber grommet has become too deformed or degraded, this grommet must then be removed and replaced prior to reinstalling the rim and tire on the vehicle. The removal of a rim from a truck, a re-tightening or replacing of the valve stem assembly, or any part thereof, and the replacement of the rim and tire onto the vehicle is labor intensive.